Cell Cycle Progression in the Pericycle Is Not Sufficient for SOLITARY ROOT/IAA14-Mediated Lateral Root Initiation in Arabidopsis thalianaw⃞
Cell Cycle Progression in the Pericycle Is Not Sufficient for SOLITARY ROOT/IAA14-Mediated Lateral Root Initiation in Arabidopsis thalianaw⃞
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DOI：
10.1105/tpc.105.035493
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发表时间：
2005-10
期刊：
影响因子：
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通讯作者：
Steffen Vanneste;B. De Rybel;G. Beemster;K. Ljung;Ive De Smet;G. Van Isterdael;M. Naudts;Ryusuke Iida;W. Gruissem;M. Tasaka;D. Inzé;H. Fukaki;T. Beeckman
中科院分区：
文献类型：
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作者：
Steffen Vanneste;B. De Rybel;G. Beemster;K. Ljung;Ive De Smet;G. Van Isterdael;M. Naudts;Ryusuke Iida;W. Gruissem;M. Tasaka;D. Inzé;H. Fukaki;T. Beeckman
为了研究生长素诱导细胞分裂的机制，以侧根起始为模型系统。通过基因芯片分析，在侧根发生的早期阶段监测了全基因组转录的变化。包括显性生长素信号转导突变体孤立根1(Slr1)，确定了参与侧根发生的基因，这些基因位于生长素/吲哚-3-乙酸(AUX/IAA)信号通路下游。有趣的是，细胞周期机制的关键组成部分在SLr1中存在严重缺陷，这表明AUX/IAA信号与核心细胞周期调控之间存在直接联系。然而，在突变背景下，通过过表达D型细胞周期蛋白(CYCD3；1)来诱导细胞周期，能够在周轮中引发完整的细胞分裂，而不会导致侧根形成。因此，只有当细胞周期激活伴随着细胞命运的重新指定时，才能发生侧根的发生。微阵列数据也证明了负反馈和正反馈机制的存在，这些机制调节着生长素的动态平衡和周轮中的信号转导，从而微调侧根起始的过程。
To study the mechanisms behind auxin-induced cell division, lateral root initiation was used as a model system. By means of microarray analysis, genome-wide transcriptional changes were monitored during the early steps of lateral root initiation. Inclusion of the dominant auxin signaling mutant solitary root1 (slr1) identified genes involved in lateral root initiation that act downstream of the auxin/indole-3-acetic acid (AUX/IAA) signaling pathway. Interestingly, key components of the cell cycle machinery were strongly defective in slr1, suggesting a direct link between AUX/IAA signaling and core cell cycle regulation. However, induction of the cell cycle in the mutant background by overexpression of the D-type cyclin (CYCD3;1) was able to trigger complete rounds of cell division in the pericycle that did not result in lateral root formation. Therefore, lateral root initiation can only take place when cell cycle activation is accompanied by cell fate respecification of pericycle cells. The microarray data also yielded evidence for the existence of both negative and positive feedback mechanisms that regulate auxin homeostasis and signal transduction in the pericycle, thereby fine-tuning the process of lateral root initiation.